I have an empty coloured cartrige and a full(new) black one.
My printer is HP-deskjet-670C
The problem is that the printer pretends as if it is printing but when the paper comes out, it is blank! even when the doccument is all black & white.

Hi there Akif
Try setting the printer to print in Grayscale as default to see if this helps. (go to printer preferences to set this)

This will stop the printer refrencing the colour crtridge when a print job is sent.

Double check to make sure that the nozzle for the cartridge is not blocked either by dried ink or a bit of the tape that covers it when you get it. Also, consider removing the empty color cartridge if the printer will still operate without it.

Thanx ErnieK and Budfred,

I will try Erniek's suggestion, but i would love to have some more possible solutions, as i suspect, there is something else wrong.

Budfred, This cartrige is new and the previous one had the same problem.
so it isn't a problem of blockage of nozzle due to some tape etc.

just a thought: the blokkage could be situated inside the printer as well, in the passage from cartridge-holder to paper.

Also: hp printers customarily print a test page to align a new print cartridge. Has this been done?

No, i haven't opted for the "Alligning the new cartrige".
I thought it useless, bec with my old cartrige, i used to do quite a lot of alligning but it never helped.

However, i'll check your first suggestion: blockage inside th printer.
Thanx.

Checking for blockage inside the printer itself is definitely something to look in to.
I use to have the same model and it was a problem at times.
HP's website still has a pretty good support section for that model too. (At least last time I looked). They had an entire section on inherent problem areas inside the printer and how to clean them.
If you ran the printer with no color cartridge installed at all for any length of time, dried ink within the printer could certainly be a problem.

Also, aligning the cartridges after installing a new one can be more important than you think! Good luck! ;)

TRY THIS WAY.GO TO START MENU,SETTING,PRINTER. RIGHT CLICK YOUR MOUSE AND DELETE/UNINSTALL YOUR PRINTER. EMPTY RECYCLE BIN.

NEXT RUN THE HP 670 CD-ROM AND RELOAD PRINTER SOFTWARE. THIS SHOULD SOLVE THE PROBLEM.

IN CASE THE ABOVE DOES NOT WORK, REPLACE YOUR COLOR CARTRIDGE.

THIS IS A VERY COMMON PROBLEM IN HP'S 640 SERIES. THIS BECOMES MORE SEVERE WHEN YOU NEED TO PRINT pdf FILES.

Replacing the colour cartridge: i have already tested this.

Reinstalling the printer software:I will try this when went home.

I haven't tried the solutions provided by other fellows in the above posts; so i'll try all the suggested solutions and will reply back after the weekend.

Thanx.

The cartridge holder is a complete hollow box.There isn't any chance of blockage in it.

The cartridge just recieves the signal to print from a band of cables; and thats all the interface it has with the printer. The mechanical arrangement of printing process is within the cartridge. U people might know all this.
But, then, I could not understand what is meant by blockage inside the "PRINTER"!

Plenty places inside a printer where a small peice of paper, leaf, paper clip etc can get hung up and end up between the cartridge head and the paper so that it tries to print, but cannot because of whatever is blocking it.

I've seen HP printers do this for no apparent reason at all too, with brand new cartridges. Swap back to an old one and it will print, both cartridges will work in another identical printer...but the new one refuses to work in a certain printer...

HP makes some excellent printers, my favorite, but sometimes they can do really strange things...